There’s more good news on the COVID-19 vaccine front today: biotechnology company Moderna reported in a press release this morning that its mRNA vaccine appeared 94.5 percent effective at preventing COVID-19 in an interim analysis of a large, Phase III trial. The news comes exactly one week after similar results came out via press release for another mRNA vaccine developed by pharmaceutical giant Pfizer and German biotech firm BioNTech.

But, while health experts are “cautiously optimistic” for this and many other vaccines in the coming months, they warn that such a timeline will not be fast enough to spare lives and health care systems from the current spike in disease.

“Right now, we are extremely concerned by the surge in cases we’re seeing in some countries,” Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization, said in a press conference Monday. “Particularly in Europe and the Americas, health workers and health systems are being pushed to the breaking point.”